Etude de la combustion de gaz de synthèse issus d'un processus de ...

Experimental study of engine-like turbulent combustion
5.2 RCM Compression-expansion
Engine-like conditions can be reproduced in a RCM when working on two strokes
mode simulating a single cycle of an internal combustion engine. Together with incylinder
pressure measurements, direct visualizations are also carried out to follow the
early stage of the ignition process.
Stationary power applications usually use natural gas as fuel, thus a methane-air
mixture, the main constituent of the natural gas, is also included in this work as a
reference fuel for comparison with the typical syngas compositions under study.
5.2.1 Sensibility analysis
tel-00623090, version 1 - 13 Sep 2011
In this section a sensibility analysis is made with the objective of evaluating the
influence of the fuel in the estimation of various parameters such as equivalent rotation
speed and ignition timing.
5.2.1.1 Piston position
The compression stroke is imposed by the RCM hydraulic system. Thus, it is not
expected to be influenced by the ignition timing and fuel type. The same is not true for
the expansion stroke that is expected to be a function of the heat release of the mixture
being burned.
In order to evaluate the influence of the ignition timing and fuel type on piston
displacement, the average the piston position signal is plotted against time in figure
5.13 for stoichiometric updraft syngas-air mixture and for various ignition timings. The
same is shown in figure 5.14 for the three fuels under study at the same ignition timing
of 12.5 ms BTDC.
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